In recent years, in the fields of production of medicines, gene therapy, regenerative medicine, immunotherapy or the like, there has been a demand for cultivating a large amount of cells, tissues, microorganisms or the like efficiently in an artificial environment.
In such cultivation of a large amount of cells, in general, cells are cultivated by using a culture container. In the cell culture by using a culture container, it is required to collect cells from the culture container after cultivation.
In the case where cultured cells (in particular, floating cells) are collected, conventionally, a method was conducted in which the total amount of a suspension of cells is collected from a culture container, and cells are then separated by centrifugation. However, this method suffers from a problem that, when a large amount of a suspension of cells is present due to the cultivation of a large amount of cells, centrifugation is required to be conducted several times in a divided manner, resulting in waste of time and effort.
On the other hand, as a technology relating to the method for collecting cells, a cell collection method used in the cell culture method disclosed in Patent Document 1 can be given, for example. In this collection method, after discharging a used culture medium supernatant from a culture container, a suspension containing cultured cells is collected, whereby a concentrated suspension of cells can be obtained.